Earth is a very big magnet-
A magnetic needle suspended horizontally by a thread freely always points north and south poles of the earth. An iron bar pivoted vertically on the ground for a long time shows a very feeble magnetic behaviour. From the analysis of those examples, it can be concluded that the earth is a huge magnet.
Earth’s magnetic field is generally caused by electric currents in the liquid outer core, which is composed of conductive, molten iron. Loops of currents in the continually moving, liquid iron create magnetic fields.
We cannot notice the magnetic field as it is invisible. We can believe it as line patterns that loop from one pool to the other pole of the planet. These discipline traces are parallel to the floor near the earth equator. They bend and converge as the sphere traces method the two magnetic poles.
The earth is huge, but most of its non-magnetic. Handiest the middle is magnetic, and you’re heaps of miles far away from it. The entire power of the earth’s area is big, but it unfolds over a giant region. That means the density of the sphere is pretty small, so small that it is difficult to detect that it is even there. You may study the way it deflects a compass needle, a totally light and carefully balanced bit of metallic, however, that’s all.
A small magnet has a far denser subject, at the least near to it. Your hand magnet can entice a compass needle far from the earth when you hold it some inches away, however, it is no longer going to have an effect on a needle from throughout the room, much less across the planet. The earth’s field will move a needle everywhere at the surface of the earth.